Despite the fact that the understanding of the human brain is still in its infancy, it appears that brain surgery is one of the oldest of the practiced medical arts. Evidence of “trepanation” can be found in archaeological remains dating back to the Neolithic period – around 10,000 BC. Trepanation (also known as trepanning, trephination, trephining or burr hole) is surgery in which a hole is drilled into the skull to expose the brain.

Cave paintings from the late Stone Age suggest that people believed the practice would cure epileptic seizures, migraines and mental disorders, perhaps in the belief that the operation would allow evil spirits to escape. There is also some evidence that such surgery was undertaken to prevent blood clots forming and to remove bone fragments following a head injury.

The following list details some of the key events and discoveries that have helped shaped our understanding of the brain today:

1st Century BC

Hippocrates, the father of modern medical ethics, wrote many texts on brain surgery. Born on the Aegean Island of Cos in 470 BC, Hippocrates was quite familiar with the clinical signs of head injuries and he was the first known person to speculate that the two halves of the brain were capable of independent processing, which he termed "mental duality".

The study of the brain suffered a setback in the seventeenth century when René Descartes, the French philosopher and founding father of modern medicine, was forced to do a deal with the Pope in order to get the bodies he needed for dissection. The Pope agreed on the understanding that Descartes would not have anything to do with the soul, mind or emotions, as those were seen as the realm of the church. Unfortunately, this agreement set the tone for Western science for the next two centuries, dividing the human experience into two distinct and separate spheres that could never overlap. Even today many people are sceptical of illnesses that are defined as being psychosomatic (illnesses where the symptoms are caused by mental processes of the sufferer).

1808

Franz Joseph Gall, a German anatomist, founded the science of phrenology, which holds that a person’s character can be determined by reading the configuration of bumps on the skull.

As peculiar as this theory may seem, it was widely accepted at the time. At the height of the phrenology craze, some people suggested that politicians should be chosen based on the shape of their skulls while others claimed to be able to detect signs of latent delinquency in children based on the bumps on their heads.

1848

A North American railway worker by the name of Phineas Gage suffered damage to the frontal lobe of his brain when it was pierced by a metal rod that shot through his skull during an explosion.

Although Gage survived the accident, he experienced profound mood and behaviour changes. A quiet, industrious worker before the accident, Gage became a surly, aggressive man who could not hold down a job.

This famous case, now found in countless neuroscience textbooks, was an important milestone in the study of the brain’s anatomy because it suggested that important parts of the personality reside in the frontal lobe. These findings indirectly lead to the development of the procedure called lobotomy, which was based on the theory that the removal of portions of the frontal lobe could cure mental derangement and depression.

1872

Charles Darwin published his book “The Expression of the Emotions in Man and Animals” in which he traces the origins of emotional responses and facial expressions in humans and animals, making note of the striking similarities between species. Later, in an unpublished notebook, Darwin proposes the theory that blushing is a clear indication of consciousness. He notes that of all the animals, only humans blush and claims that this is because they are the only ones capable of self-consciously imagining what others are thinking of them.